QED: Electric Field - Can We Observe Photons?

[Gavroy]

hi

i heard some things about quantum electrodynamics and one thing was that they gave up the concept of actual fields and said that the electromagnetic information from one particle to the other is transported by photons.

Now my question is: Can one observe these photons or is it just a mathematical concept?

 

[QuantumClue]

hi

i heard some things about quantum electrodynamics and one thing was that they gave up the concept of actual fields and said that the electromagnetic information from one particle to the other is transported by photons.

Now my question is: Can one observe these photons or is it just a mathematical concept?

There may be some terminology here I have forgotten as I don't quite understand the idea that we have given up the concept of fields... but as far as I am aware, quantum fields by definition cover all spacetime. They permeate every corner of spacetime, and this is what a quantum field is.

As for being able to observe photons, we are yet to directly observe any particle. We have imaging computers which can take rather serious scans of particles at very small levels. Some consider this as good as an observation, others don't. When we talk of photons being shared between electrons, these photons are usually virtual photons. We cannot see them, but we know they exist because they have real effects in the world around us on the very small scales.

 

[A. Neumaier]

the electromagnetic information from one particle to the other is transported by photons.

Now my question is: Can one observe these photons or is it just a mathematical concept?

https://www.physicsforums.com/showthread.php?t=75307&highlight=virtual+particles
has a long discussion on this.

Chapter A7 of http://arnold-neumaier.at/physfaq/physics-faq.html#A7
provides a summary.